Chemical reaction method

ABSTRACT

A chemical reaction method having steps of preparing a chemical reaction apparatus by partitioning an inside of a horizontal flow reactor into multiple chambers by multiple partition plates, and flowing a liquid horizontally with an unfilled space being provided thereabove, generating microwaves with a microwave generator, and transmiting the microwaves, with at least one waveguide, to the unfilled space in the reactor. Also forming a top portion of the partition plates act as a weir, inclining the reactor such that, in each of the chambers, a weir height on the inlet side is higher than a weir height on the outlet side by at least an overflow depth at the partition plate on the outlet side, flowing content over each of the partition plates inside the reactor, and configuring the weir heights of the partition plates in the reactor are the same in a state where the reactor is not inclined.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of U.S. Ser. No.14/357,145 filed on May 8, 2014, which is a U.S. National PhaseApplication under 35 U.S.C. § 371 of International Patent ApplicationNo. PCT/JP2012/079152 filed on Nov. 9, 2012, and claims benefit ofpriority to Japanese Patent Application No. JP 2011-247954 filed on Nov.11, 2011. The International Application was published on May 16, 2013,as International Publication No. WO 2013/069778 under PCT Article 21(2).The entire contents of these applications are hereby incorporated byreference.

TECHNICAL FIELD

The present invention relates to a chemical reaction apparatus forirradiating microwaves in a reactor.

BACKGROUND

Conventionally, chemical reaction apparatuses and chemical reactionmethods are known that perform heat treatment and the like byirradiating a reaction material with microwaves (electromagnetic waves)(see JP 2006-516008A (Tokuhyo), for example).

SUMMARY Technical Problem

In such conventional chemical reaction apparatuses, there has been ademand for preventing an unreacted content from being discharged.

The present invention was arrived at in view of these circumstances, andit is an object thereof to provide a chemical reaction apparatus capableof preventing an unreacted content from being discharged, by preventingthe content from flowing in a shortcut in a horizontal flow-typereactor.

Solution to Problem

In order to achieve the above-described object, the present invention isdirected to a chemical reaction apparatus, including: a horizontalflow-type reactor inside of which has been partitioned into multiplechambers by multiple partition plates, and a liquid content horizontallyflows with an unfilled space being provided thereabove; a microwavegenerator that generates microwaves; and at least one waveguide thattransmits the microwaves generated by the microwave generator to theunfilled space in the reactor; wherein the content flows over each ofthe partition plates, and in each of the chambers, a weir height on aninlet side is higher than a weir height on an outlet side by at least anoverflow depth at the partition plate on the outlet side.

With this configuration, at least some of overflows at the respectivepartition plates do not have the same height. Accordingly, the overflowscan be prevented from being directly connected, and a content can beprevented from flowing in a shortcut. As a result, an unreacted contentcan be prevented from being discharged.

Furthermore, the chemical reaction apparatus of the present inventionmay be such that the weir heights of the partition plates in the reactorare the same in a state where the reactor is not inclined, and, when thecontent flows, the reactor is inclined such that, in each of thechambers, the weir height on the inlet side is higher than the weirheight on the outlet side by at least the overflow depth at thepartition plate on the outlet side.

With this configuration, even in the case where the partition plateshave the same weir height, content can be prevented from flowing in ashortcut by making the reactor inclined.

Furthermore, the chemical reaction apparatus of the present inventionmay be such that the flow paths have the same shape and are provided inthe same number at all of the multiple partition plates, an angle of theinclination is at least θ that is calculated as: θ=sin⁻¹(H/L) (where Lis a shortest length of lengths, in a length direction of the reactor,of the respective chambers, and H is an overflow depth obtained usingthe following equation:15eQ=√{square root over (2g)}CN{4(b−a)H ^(5/2)+10aeH ^(3/2)}

where Q is a flow rate, a is a width of a bottom of a trapezoidal flowpath, b is a width of an upper side of the trapezoidal flow path, e is aheight from the bottom to the upper side of the trapezoidal flow path, Cis a flow coefficient, N is a number of the trapezoidal flow pathsformed at one partition plate, and g is an acceleration of gravity).

With this configuration, the inclination angle of the reactor can becalculated by determining the flow rate and the shape of the flow pathat the partition plates. A content can be prevented from flowing in ashortcut by making the reactor inclined according to this inclinationangle.

Furthermore, the chemical reaction apparatus of the present inventionmay be such that the reactor is not inclined, and, in each of thechambers, a height of a bottom of a flow path at the partition plate onan inlet side is higher than a height of a bottom of a flow path at thepartition plate on an outlet side by at least an overflow depth at thepartition plate on the outlet side.

With this configuration, even in the case where the reactor is notinclined, a content can be prevented from flowing in a shortcut bysetting as appropriate the heights of the flow paths at the partitionplates.

Furthermore, the chemical reaction apparatus of the present inventionmay be such that the overflow depth is H that is calculated using thefollowing equation:15eQ=√{square root over (2g)}CN{4(b−a)H ^(5/2)+10aeH ^(3/2)}

(where Q is a flow rate, a is a width of a bottom of a trapezoidal flowpath, b is a width of an upper side of the trapezoidal flow path, e is aheight from the bottom to the upper side of the trapezoidal flow path, Cis a flow coefficient, N is a number of the trapezoidal flow pathsformed at one partition plate, and g is an acceleration of gravity).

With this configuration, the overflow depth can be calculated bydetermining the flow rate and the shape of the flow path at thepartition plates, and a difference in the height of the bottom of theflow path between adjacent partition plates can be seen. A content canbe prevented from flowing in a shortcut by forming the flow paths at thepartition plates according to the difference in the height of the bottomof the flow path between the partition plates.

Furthermore, the chemical reaction apparatus of the present inventionmay further include at least one agitation unit that rotationallyagitates the content inside the reactor.

With this configuration, a content is agitated, and, thus, the contentinside the reactor can be more uniformly irradiated with microwaves. Asa result, for example, a situation can be avoided in which only part ofthe content inside the reactor is irradiated with microwaves.

The present invention provides a chemical reaction apparatus capable ofpreventing an unreacted content from being discharged, by preventing thecontent from flowing in a shortcut in a horizontal flow-type reactor.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing the configuration of a chemical reactionapparatus according to Example 1 of the present invention.

FIG. 2 is a view showing an exemplary internal configuration of areactor according to the example.

FIG. 3A is a perspective view showing an exemplary shape of the reactoraccording to the example.

FIG. 3B is a perspective view showing an exemplary shape of the reactoraccording to the example.

FIG. 3C is a perspective view showing an exemplary shape of the reactoraccording to the example.

FIG. 3D is a perspective view showing an exemplary shape of the reactoraccording to the example.

FIG. 4A is a view showing an exemplary shape of a partition plateaccording to the example.

FIG. 4B is a view showing an exemplary shape of the partition plateaccording to the example.

FIG. 4C is a view showing an exemplary shape of the partition plateaccording to the example.

FIG. 4D is a view showing an exemplary shape of the partition plateaccording to the example.

FIG. 5A is a view showing an exemplary shape of a flow path according tothe example.

FIG. 5B is a view showing an exemplary shape of the flow path accordingto the example.

FIG. 5C is a view showing an exemplary shape of the flow path accordingto the example.

FIG. 6A is a view illustrating a relationship between the partitionplates and overflows according to the example.

FIG. 6B is a view illustrating a relationship between the partitionplates and overflows according to the example.

FIG. 6C is a view illustrating a relationship between the partitionplates and overflows according to the example.

FIG. 7 is a view showing a trapezoidal flow path according to theexample.

FIG. 8 is a view illustrating a relationship between the partitionplates and overflows according to the example.

FIG. 9 is a view illustrating a relationship between an overflow depth,an inclination angle, and the like according to the example.

FIG. 10 is a view showing an exemplary internal configuration of thereactor that is inclined according to the example.

FIG. 11 is a view showing another exemplary microwave generator andwaveguide according to the example.

FIG. 12A is a view illustrating a position for microwave irradiationaccording to the example.

FIG. 12B is a view illustrating positions for microwave irradiationaccording to the example.

DETAILED DESCRIPTION

Hereinafter, a chemical reaction apparatus according to the presentinvention will be described by way of an example. Note that constituentelements denoted by the same reference numerals are the same or similarto each other in the following example, and, thus, a description thereofmay not be repeated.

Example 1

Below, a chemical reaction apparatus according to Example 1 of thepresent invention will be described with reference to the drawings. Thechemical reaction apparatus according to this example irradiates thecontent of a reactor with microwaves.

FIG. 1 is a diagram showing the configuration of a chemical reactionapparatus 1 according to this example. The chemical reaction apparatus 1according to this example includes a mixing portion 12, a reactor 13,microwave generators 14, waveguides 15, a microwave control portion 16,a catalyst separating portion 17, and a treated liquid storage tank 18.

The mixing portion 12 mixes a raw material and a solid catalyst. Themixing portion 12 may mix the raw material and the like with a reactant.The raw material may contain multiple materials. For example, in thecase of performing esterification in the reactor 13, fat and oils andalcohol may be used as the raw material. The raw material and the solidcatalyst may be supplied to the mixing portion 12 by pumps 11 as shownin FIG. 1, or may be supplied to the mixing portion 12 using othermethods. The mixing portion 12 may mix two or more materials, forexample, by rotating a blade-like member, a wing-like member, or ascrew-like member. Note that, although this example describes the casein which the catalyst that is to be mixed with the raw material is asolid catalyst (heterogeneous catalyst), the catalyst may be a liquidcatalyst (homogeneous catalyst). Furthermore, the solid catalyst may ormay not form a fluidized bed inside the reactor 13. Furthermore, thereis no limitation on the shape of the solid catalyst. Examples of theshape of the solid catalyst include various grains, a cylinder (that mayor may not be hollow), a sphere, a pellet, a ring, a shell, and othershapes. Furthermore, the solid catalyst may or may not be, for example,microwave-absorbing or microwave-sensitive. If the solid catalyst ismicrowave-absorbing or microwave-sensitive, when microwaves areirradiated inside the reactor 13 (described later), the solid catalystis heated by the microwaves, and the chemical reaction near the solidcatalyst is facilitated. Note that the microwave absorptivity and themicrowave sensitivity depend on the frequency of microwaves used forirradiation, the temperature inside the reactor 13, and the like. Thatis to say, materials that have a high dielectric loss factor, at thefrequency of microwaves used and the temperature inside the reactor 13in which the raw material is to undergo a reaction, provide a highmicrowave absorptivity. Accordingly, for example, a solid catalystcontaining such a highly microwave-absorbing material may be used. Forexample, if microwaves at 2.45 GHz are irradiated, examples of themicrowave-absorbing material include carbon except for fullerene (e.g.,graphite, carbon nanotube, activated carbon, etc.), iron, nickel,cobalt, ferrite, and the like. Accordingly, the solid catalyst maycontain such a microwave-absorbing material. Specifically, the solidcatalyst may be a composite in which such a microwave-absorbing ormicrowave-sensitive material and a metal or metal oxide are combined, acomposite in which such a microwave-absorbing or microwave-sensitivematerial and a catalyst such as alkali catalyst or acid catalyst arecombined, or a composite in which a microwave-absorbing ormicrowave-sensitive material, a catalyst such as alkali catalyst or acidcatalyst, and a metal or metal oxide are combined. The composite may beformed, for example, through physical adsorption, chemical bonding,alloying, or other methods. Furthermore, in the mixing portion 12,preliminary heating may or may not be performed for preparation for thereaction in the reactor 13. In the case of performing the preliminaryheating, the temperature in the preliminary heating in the mixingportion 12 is preferably controlled such that the raw material and thelike at the time of entering the reactor 13 are at a desired temperatureor in a desired temperature range. Note that, in the case of notperforming the preliminary heating in the mixing portion 12, heatingcorresponding to the preliminary heating may be performed in the reactor13. The raw material and the solid catalyst mixed by the mixing portion12 are loaded into the upstream side in the reactor 13.

The reactor 13 is a horizontal flow-type reaction unit in which a liquidcontent horizontally flows with an unfilled space being providedthereabove. The reactor 13 in which the content horizontally flowsrefers to a reactor that is not a vertical flow-type reaction unit inwhich the content vertically flows, that is, the content does not haveto strictly horizontally flow. It is sufficient that the content flowsin a direction close to the horizontal direction on the whole. Examplesof the content include a mixture of the raw material and the catalyst.The raw material and the catalyst mixed by the mixing portion 12 flowinside the reactor 13. Note that, since the chemical reaction in thereactor 13 produces a product material from the raw material, thecontent of the reactor 13 may be considered to contain the productmaterial. That is to say, the content may be referred to as the rawmaterial and/or the product material. Furthermore, since an unfilledspace is present above the content, the content is typically a materialother than gas. Furthermore, the content can flow inside the reactor 13and has a flat liquid surface, and, thus, the content is a materialother than solid (e.g., powders or grains, etc.). Accordingly, thecontent is liquid. The liquid content may be for example, a materialhaving a high flowability such as water, oil, aqueous solution, orcolloidal solution, or may be a material having a low flowability suchas slurry or suspension. It is preferable that the liquid surface of thecontent inside the reactor 13 is kept horizontal, and, thus, even in thecase where the flowability of the liquid content is low, it preferablyallows the liquid surface to be horizontal after a while without theapplication of vibration from the outside. That is to say, the liquidcontent preferably has a flowability that allows the shape of thesurface to be changed without vibration from the outside. Note that theliquid surface being horizontal may refer to the state of beingcompletely flat, or may refer to the state of being flat on the wholealthough there are slightly rough portions. The reason for this is that,if the content does not have a high flowability, the liquid surface maynot be completely flat. The inner wall of the reactor 13 is preferablymade of a microwave-reflecting material. Examples of themicrowave-reflecting material include metal. The internal configurationof the reactor 13 will be described later.

The microwave generators 14 generate microwaves. The chemical reactionapparatus 1 according to this example may include one microwavegenerator 14, or may include two or more microwave generators 14. Thereis no limitation on the frequency of the microwaves, and examplesthereof include 2.45 GHz, 5.8 GHz, 24 GHz, 913 MHz, and otherfrequencies ranging from 300 MHz to 300 GHz.

The one or more waveguides 15 transmit the microwaves generated by themicrowave generators 14 to the unfilled space in the reactor 13. Thenumber of waveguides 15 provided may be the same as the number ofmicrowave generators 14 as shown in FIG. 1. Furthermore, the waveguide15 may be branched and transmit the microwaves to two or more positionsin the unfilled space. Note that the specification of the waveguides 15is preferably in accordance with the frequency of the microwavesgenerated by the microwave generators 14.

The microwave control portion 16 controls the power of microwaves usedfor irradiation in the reactor 13, according to the temperature measuredby temperature measuring portions 25 (described later). The control bythe microwave control portion 16 makes it possible to keep inside thereactor 13 at a desired temperature or in a desired temperature range.

The catalyst separating portion 17 separates the catalyst from theproduct material after the reaction in the reactor 13. If the catalystthat has been mixed with the raw material is a solid catalyst, forexample, filtering may be used to separate the solid catalyst, or one ofthe solid catalyst and the product material may be precipitated toseparate the solid catalyst. Furthermore, if the solid catalyst containsa magnetic substance, a magnet (that may be a permanent magnet or may bean electromagnet) for attracting the solid catalyst may be used toseparate the solid catalyst. Note that the separated solid catalyst maybe used again as appropriate. Furthermore, if a liquid catalyst is used,distillation, extraction, or neutralization may be performed in thecatalyst separating portion 17 to separate the catalyst.

The product material from which the catalyst has been separated by thecatalyst separating portion 17 is loaded into the treated liquid storagetank 18. Then, this product material is separated as appropriate into afinal product, a by-product, and the like. For example, if the rawmaterial is free fatty acid, and esterification is performed in thereactor 13, a product that is biodiesel fuel and a by-product that iswater are obtained. In this case, an acid catalyst is used. Furthermore,for example, if the raw material is triglyceride, andtransesterification is performed in the reactor 13, a product that isbiodiesel fuel and a by-product that is glycerin are obtained. In thiscase, an alkali catalyst is used.

Note that an unshown cooler that cools down the material after thereaction in the reactor 13 may or may not be provided on the path afterthe reactor 13. In the former case, for example, the cooler may usewater to cool down the material after the reaction in the reactor 13.

FIG. 2 is a view showing an exemplary internal structure of the reactor13 according to this example. In FIG. 2, the inside of the reactor 13 ispartitioned by multiple partition plates 21 into multiple chambers 31,32, 33, and 34. The multiple chambers 31, 32, 33, and 34 are chambersthat are continuously arranged in series. As described above, anunfilled space 22 is present in the upper portion inside the reactor 13.The unfilled space 22 is irradiated with the microwaves generated by themicrowave generators 14 and transmitted via the waveguides 15. Note thatFIG. 2 shows the case in which a single unfilled space is present insidethe reactor 13, that is, the case in which an unfilled space is sharedby all the chambers 31 to 34, but there is no limitation to this. Thatis to say, an unfilled space may be shared by at least two or morechambers that are part of all chambers, or may be shared by none of thechambers (in this case, there are unfilled spaces that have beenseparated from each other by the partition plates 21). The waveguides 15may or may not be provided respectively at the upstream positions in thechambers 32, 33, and 34 as shown in FIG. 2. In the former case, forexample, the microwaves that have been transmitted by one waveguide 15to the unfilled space 22 are mainly irradiated on the chamber presenttherebelow. Since microwaves are transmitted through an unfilled space,for example, the microwaves that have been transmitted by the waveguide15 at the position of the chamber 32 are irradiated via the unfilledspace also on the content in the chamber 31 and the chamber 33. Notethat the waveguides 15 may be provided at the positions of the partitionplates 21, that is, at the positions above the partition plates 21.Accordingly, the microwaves that have been transmitted by one waveguide15 to the unfilled space 22 are mainly irradiated on two chambers thathave been partitioned from each other by the partition plate 21 at theposition corresponding to that waveguide 15. If the unfilled space 22 isshared by multiple chambers, the microwaves that have been transmittedto the shared unfilled space 22 are irradiated on a content 20 in themultiple chambers sharing the unfilled space 22. The partition plates 21may transmit microwaves, may absorb microwaves, or may reflectmicrowaves. Examples of the microwave-transmitting material includeTeflon (registered trademark), quartz glass, ceramic, siliconnitride-alumina, and the like. Accordingly, the partition plates 21 thattransmit microwaves may be made of such a microwave-transmittingmaterial. Furthermore, examples of the microwave-absorbing materialinclude carbon except for fullerene, and the like. Accordingly, thepartition plates 21 that absorb microwaves may be made of such amicrowave-absorbing material. Furthermore, examples of themicrowave-reflecting material include metal. Accordingly, the partitionplates 21 that do not transmit microwaves may be made of such amicrowave-reflecting material. Furthermore, the partition plates 21 maybe made of a combination of two or more freely selected from themicrowave-transmitting material, the microwave-absorbing material, andthe microwave-reflecting material.

Furthermore, as shown in FIG. 2, the chemical reaction apparatus 1 mayfurther include agitation units 23. That is to say, the chemicalreaction apparatus 1 according to this example may include one or moreagitation units 23 that rotationally agitate the content 20 inside thereactor 13. FIG. 2 shows the case in which the chambers 31 to 34respectively have the agitation units 23, but there is no limitation tothis. One or more chambers may not have the agitation unit 23.Furthermore, FIG. 2 shows the case in which each of the agitation units23 is in the shape of a blade, but this merely schematically shows theagitation units 23. The agitation may be performed, for example, byrotating a blade-like, wing-like, or rod-like rotatable member. Therotatable member may be made of a microwave-transmitting material, amicrowave-absorbing material, a microwave-reflecting material, or acombination of two or more freely selected from themicrowave-transmitting material, the microwave-absorbing material, andthe microwave-reflecting material. The rotation may be performed, forexample, by rotating a rotatable member attached to a shaft inaccordance with the rotation of the shaft, or by rotating the rotatablemember using a magnetic force as in the case of a magnetic stirrer. Inthe former case, the shaft may be provided independently for eachchamber, or may be shared by multiple chambers. In the latter case, therotatable member (magnetic stirrer) in the shape of a rod, a blade, awing, or the like is rotated by a magnet. The agitation of the contentby the agitation units 23 may be used to cause the content to flow fromthe upstream side to the downstream side, or in the opposite direction,but there is no limitation to this. Note that rotational agitation isalready known, and, thus, a detailed description thereof has beenomitted.

Hereinafter, reasons why the content of the reactor 13 is rotationallyagitated by the agitation units 23 will be briefly described. A firstreason why the content is agitated by the agitation units 23 is touniformly heat the content with microwaves. Although depending on thetype of content and the temperature of the content, the depth to whichmicrowaves penetrate is fixed, and, thus, the agitation is performed inorder to uniformly irradiate and uniformly heat the entire content withmicrowaves. Furthermore, the content can be more efficiently irradiatedwith microwaves as the surface area of the content at the unfilled space22 increases. Accordingly, a second reason why the content is agitatedis to increase the area subjected to microwave irradiation. Thus, thecontent is agitated by the agitation units 23 preferably at an intensitythat allows the surface of the content at the unfilled space 22 to bedisordered, but there is no limitation to this (if the agitation isperformed for the first reason, it may be sufficient that the entirecontent is eventually heated). Furthermore, since the raw material andthe like are agitated using the agitation units 23 in this manner, evenin the case where a raw material contains two or more materials havingdifferent densities, these materials can be mixed and reacted with eachother as appropriate. For example, when causing materials havingdifferent densities, such as alcohol and waste oil, to react with eachother in a vertical flow-type reactor, these materials are easilyseparated from each other. However, as in this example, if the reactor13 is of a horizontal flow-type and is provided with the agitation units23, these materials can be mixed and reacted with each other asappropriate.

Furthermore, as shown in FIG. 2, the reactor 13 also may have thetemperature measuring portions 25. That is to say, the chemical reactionapparatus 1 according to this example may have the temperature measuringportions 25 that measure the temperature inside the reactor 13. Thetemperature inside the reactor 13 is preferably the temperature of thecontent of the reactor 13. FIG. 2 schematically shows the case in whichthe chambers 31 to 34 respectively have the temperature measuringportions 25, but there is no limitation to this. One or more chambersmay not have the temperature measuring portion 25. Furthermore, FIG. 2merely schematically shows the temperature measuring portions 25. Thetemperature measuring portions 25 may measure the temperature, forexample, using a thermocouple, an infrared sensor, an optical fiber, orother methods. The temperature measured by the temperature measuringportions 25 (strictly speaking, data indicating the temperature) ispassed to the microwave control portion 16, and is used to control thepower of microwaves from the microwave generators 14. As describedabove, this control may be control for keeping the temperature of thechambers 31 to 34 at a desired temperature or in a desired temperaturerange. For example, if microwaves are irradiated on the position of eachpartition plate 21, the power of microwaves irradiated on that positionmay be controlled, for example, using one or both of the temperatures oftwo chambers that have been partitioned from each other by the partitionplate 21 at the position subjected to the microwave irradiation. In theformer case, for example, the control may be performed using a lowertemperature, using a higher temperature, or using a temperature of achamber specified in advance. In the latter case, for example, thecontrol may be performed using an average of these temperatures, orusing a weighted average according to the capacities of both chambers(average in consideration of weights according to the capacities of thechambers).

Furthermore, the wall face of the reactor 13 may be covered by a heatinsulating material. In that case, heat inside the reactor 13 can beprevented from being dissipated to the outside.

FIGS. 3A and 3B are views showing an exemplary shape of the reactor 13according to this example. In FIGS. 3A and 3B, the partition plates 21,the agitation units 23, and the like have been omitted for the sake ofconvenience of the description. In FIGS. 3A and 3B, the reactor 13according to this example has a shape in which the area of the liquidsurface does not change even in the case where the height of the liquidsurface changes according to a change in the amount of the content. Notethat “the area of the liquid surface does not change even in the casewhere the height of the liquid surface changes according to a change inthe amount of the content” refers to that there is at least the range ofthe content within which the area of the liquid surface does not changeeven in the case where the amount of the content changes. Accordingly,it is conceivable that the area of the liquid surface does not changeaccording to the amount of the content regardless of the amount of thecontent, or that the area of the liquid surface does not changeaccording to the amount of the content as long as the amount of thecontent is within a predetermined range, that is, as long as the amountof the content is between a first amount and a second amount (assumingthat the second amount is larger than the first amount). In thisexample, the latter case will be mainly described. That is to say, inthis example, the reactor 13 has a shape in which the area of the liquidsurface does not change according to a change in the amount of thecontent as long as the amount of the content is within a predeterminedrange. Accordingly, the reactor 13 may have a shape in which thecross-section in the liquid surface direction of the content does notchange as long as the amount of the content is within a predeterminedrange, for example, as shown in FIGS. 3A and 3B. In this case, withinthe range of the height of the liquid surface when the amount of thecontent changes from the first amount to the second amount, the shape inthe horizontal direction inside the reactor 13 corresponding to theheight of the liquid surface does not change. Note that theabove-described first amount is typically the lower limit value of thecontent in the case where the area of the liquid surface does notchange, and the second amount is typically the upper limit value of thecontent in the case where the area of the liquid surface does notchange. Furthermore, even when the content is at the second amount, anunfilled space has to be present above the content. The reason for thisis that microwaves are irradiated via an unfilled space in the reactor13. Furthermore, the liquid surface may be disordered when agitation isperformed inside the reactor 13 as described above, but the liquidsurface described here is the liquid surface without such disorder orthe like. Note that “the height of the liquid surface” is the height ofthe liquid surface in the vertical direction.

In FIG. 3A, the reactor 13 has a semicylindrical shape elongated in theflow direction and projecting downward. That is to say, the reactor 13in FIG. 3A has a shape in which an open-topped semicylinder projectingdownward and an open-bottomed rectangular solid having the same lengthas the semicylinder are joined at their openings. Note that the openingof the semicylinder and the opening of the rectangular solid have thesame size and the same shape, and they are joined at their openings toform the reactor 13. In other words, the reactor 13 in FIG. 3A has ahollow shape having a side face with a U-shaped cross-section and anupper face with a cross-section closing the opening of the U-shape,wherein the openings at both ends of the hollow shape are closed by flatfaces perpendicular to the length direction. In the reactor 13 in FIG.3A, the area of the liquid surface does not change as long as the heightof the liquid surface of the content is within a range R1 (e.g., theheights at a level 1, at a level 2, etc.). Note that the height of theliquid surface at the lowest level in the range R1 corresponds to thelowest position in the rectangular solid forming the upper portion ofthe reactor 13.

In FIG. 3B, the reactor 13 is in the shape of a rectangular solid. Inthe reactor 13 in FIG. 3B, the area of the liquid surface does notchange as long as the height of the liquid surface of the content iswithin the range R1, which covers the entire height (e.g., the heightsat the level 1, at the level 2, etc.). That is to say, the area of theliquid surface does not change regardless of the amount of the content.

Next, the partition plates 21 will be described. The content 20 such asa raw material loaded into the reactor 13 flows through the chambers 31to 34 and is finally discharged from the downstream side (the right endof the reactor 13 in FIG. 2). Note that a flow path that allows thecontent to flow is formed at the partition plates 21. In this example,the flow path is an overflow-type flow path formed above the partitionplates 21. That is to say, in this example, the content flows over eachof the partition plates 21. The flow path allows the content to flowfrom the upstream side (the left side in FIG. 2) to the downstream side(the right side in FIG. 2) in the reactor 13. FIGS. 4A and 4B are viewsshowing the partition plate 21 provided in the reactor 13 in the shapeas shown in FIG. 3A, in the length direction of the reactor 13. Thepartition plate 21 does not extend to the position of the unfilled space22, and the content flows through that position (that is, over thepartition plate 21). The number of overflow-type flow paths may be threeas shown in FIG. 4A, may be one as shown in FIG. 4B, or may be othernumbers (two, or four or more). Furthermore, each flow path may betrapezoidal as shown in FIGS. 4A, 4B, and 5A, may be V-shaped as shownin FIG. 5B (wedge-shaped), may be quadrangular (rectangular) as shown inFIG. 5C, or may be in other shapes (e.g., U-shaped, semicircular, etc.).If the partition plate 21 has multiple flow paths, the flow paths mayhave different shapes, or may have the same shape. Furthermore, if thepartition plate 21 has multiple flow paths, the bottoms of the flowpaths (the lowest points of the flow paths) preferably have the sameheight. The height position of the bottom of a flow path may be referredto as a “weir height”. In FIGS. 5A to 5C, the position indicated by theleft-pointing arrow is the weir height (the height position of thebottom of a flow path). The weir height indicates the height in thevertical direction. Furthermore, if the flow path is rectangular, thewidth of the flow path may be the same as the width of the reactor 13.That is to say, the partition plate 21 in that case has, on the upperside thereof, no recess such as cutout (portion that has been cut out),and a flow path is formed throughout the width of the reactor 13(full-width weir). Although FIGS. 4A and 4B each show a partition platein the case where the unfilled space 22 is shared by two chambers thathave been partitioned from each other by that partition plate 21, thepartition plate 21 may extend also to the position of the unfilled space22, in the case where the unfilled space 22 is not shared. For example,in the partition plate 21 in FIGS. 4A and 4B, the partition plate mayextend to above the upper side of the trapezoidal flow path. That is tosay, the partition plate 21 may have multiple trapezoidal holes inaccordance with flow paths. Also in that case, in the flow pathsrespectively formed by the holes, the content may be regarded as flowingover the partition plate 21. It will be appreciated that, if the reactor13 has a shape other than that in FIG. 3A, the partition plate 21 isshaped in accordance with that shape of the reactor 13. Furthermore, ifthere are multiple partition plates 21 inside the reactor 13, thepartition plates 21 may have the same shape, or may have differentshapes. Furthermore, the partition plate 21 has a thickness of, forexample, approximately 1 to 20 mm, which is sufficiently smaller thanthe length of each chamber (the length in the length direction of thereactor 13).

(1) The Case in which the Reactor is not Inclined and there is a HeightDifference Between the Partition Plates

Next, the weir heights of the partition plates 21 in the case where thereactor 13 is not inclined will be described. In this case, adescription will be made focusing on the chamber 33, but the same isapplicable to the other chambers. As shown by the partition plate 21 onthe right side in FIG. 6A, in an overflow-type flow path, the height ofthe content 20 is higher than the weir height of the partition plate 21by an overflow depth H. The overflow depth is the height of an overflowwhen the content flows through the flow path over the partition plate21, that is, the height from the weir height to the highest position inthe content (the height in the vertical direction). In FIGS. 5A to 5C,the overflow depth is indicated by H. Furthermore, in the case as shownin FIG. 6A where the reactor 13 is not inclined and the partition plate21 on the inlet side (the left side in the drawing) of the chamber 33and the partition plate 21 on the outlet side (the right side in thedrawing) have the same weir height, the partition plate 21 on the inletside of the chamber 33 and the partition plate 21 on the outlet sidehave the same overflow height, and the overflows at the partition plates21 are directly connected in the left-right direction. Accordingly, atleast part of the content 20 may move from the chamber 32 to the chamber34 without being retained in the chamber 33 due to the directlyconnected overflows. That is to say, in the case of FIG. 6A, the content20 may flow in a shortcut and be discharged from the chamber 33.Furthermore, also in the case as shown in FIG. 6B where the weir heightof the partition plate 21 on the inlet side of the chamber 33 is higherthan the weir height of the partition plate 21 on the outlet side but atleast part (shaded portion in the drawing) of the overflows at thepartition plates 21 are directly connected in the left-right direction,at least part of the content 20 may flow in a shortcut without beingretained in the chamber 33 due to the directly connected overflows. Onthe other hand, in the case as shown in FIG. 6C where the weir height ofthe partition plate 21 on the inlet side of the chamber 33 is higherthan the weir height of the partition plate 21 on the outlet side by theoverflow depth H on the outlet side, the overflows at the partitionplates 21 are not directly connected in any portion in the left-rightdirection. In this case, when the content 20 flows into chamber 33 overthe partition plate 21 on the inlet side, all the content 20 moves atleast downward. Thus, according to a decrease in the potential energydue to that movement, the content 20 that has flown into the chamber 33sinks toward the bottom of the chamber 33. Accordingly, in the case ofFIG. 6C, the content 20 that has flown into the chamber 33 via theoverflow on the inlet side hardly flows out as it is via the overflow onthe outlet side, compared with the cases of FIGS. 6A and 6B. Thus, itseems that the content 20 can be effectively prevented from flowing in ashortcut. Accordingly, it is sufficient that, in each chamber of thereactor 13, the weir height on the inlet side is higher than the weirheight on the outlet side by at least the overflow depth H at thepartition plate 21 on the outlet side. Accordingly, the content 20 canbe prevented from flowing in a shortcut in each chamber. In order toachieve this, as described in FIG. 6C, the partition plates 21 may beused in which the height of the bottom of the flow path (weir height) atthe partition plate 21 on the inlet side is higher than the height ofthe bottom of the flow path (weir height) at the partition plate 21 onthe outlet side by at least the overflow depth H at the partition plate21 on the outlet side, in each chamber of the reactor 13 that is notinclined. Furthermore, as described later, the weir height on the inletside may be made higher than the weir height on the outlet side by atleast the overflow depth H at the partition plate 21 on the outlet sidein each chamber of the reactor 13, by making the reactor 13 inclined.Furthermore, if the weir height of the partition plate 21 on the inletside of the chamber 33 is higher than the weir height of the partitionplate 21 on the outlet side by the overflow depth H on the outlet sidein this manner, a reversed flow also can be prevented. Note that, inFIGS. 6A to 6C, the agitation units 23 and the temperature measuringportions 25 have been omitted for the sake of convenience of thedescription. Furthermore, portions of the partition plates 21 above theweir height also have been omitted for the sake of convenience of thedescription.

Next, the overflow depth H will be described. Below, a case will bedescribed in which the partition plate 21 has N trapezoidal flow pathsshown in FIG. 7. It is assumed that the N flow paths have the same shapeand the same weir height. Note that, in the trapezoidal flow path inFIG. 7, if a width a of the bottom of the trapezoidal flow path is equalto a width b of the upper side, that is, if a=b, the flow path isrectangular. Furthermore, if the width a of the bottom of thetrapezoidal flow path is 0, that is, if a=0, the flow path is V-shaped.Note that the height of the trapezoidal flow path is taken as e, and thez axis is set vertically downward from the upper face of the overflow.In this case, D(z) is represented by the following equation.

${D(z)} = {{{- \frac{b - a}{e}}z} + {\frac{b - a}{e}H} + a}$

Using Bernoulli's theorem v=(2 gz)^(1/2), a flow rate Q is representedby the following equation. In the equation, g is an acceleration ofgravity, C is a flow coefficient, and v is a fluid velocity. The flowcoefficient is determined according to the shape of the flow path, and,for example, may be calculated by experiment, or may be calculated bycomputation.Q=∫ ₀ ^(H) CND(z)√{square root over (2gz)}dz

If D(z) above is substituted for this equation and integration isperformed with z, the following equation is obtained.

$Q = {\frac{{CN}\sqrt{2\; g}}{15\; e}\left\{ {{4\left( {b - a} \right)H^{\frac{5}{2}}} + {10\; a\; e\; H^{\frac{3}{2}}}} \right\}}$This equation can be rewritten as follows.15eQ=√{square root over (2g)}CN{4(b−a)H ^(5/2)+10aeH ^(3/2)}

The overflow depth H can be calculated by solving this equation.Furthermore, if the flow paths are provided in the same number and havethe same shape at the partition plates in the reactor 13, the partitionplates 21 have the same overflow depth H. Accordingly, if the partitionplates 21 are designed such that the height of the bottom of the flowpath (weir height) at the partition plate 21 on the inlet side is higherthan the height of the bottom of the flow path (weir height) at itsadjacent partition plate 21 on the outlet side by at least the overflowdepth H, the content can be prevented from flowing in a shortcut in thereactor 13, and, thus, an unreacted content can be prevented from beingdischarged out of the reactor 13.

It is preferable that the height of an outlet in the last chamber 34 hasthe same relationship as that of the weir height described above. Thatis to say, it is preferable that, in the last chamber 34, the height ofthe bottom of the flow path (weir height) at the partition plate 21 onthe inlet side is higher than the height of the bottom of the flow pathat the outlet by at least the overflow depth at the outlet. The shape ofa flow path at the partition plates 21 is typically different from theshape of the outlet in the last chamber 34, and, thus, the overflowdepth at the outlet may be computed separately from the overflow depth Hat the partition plates 21. The overflow depth of a trapezoidal flowpath can be calculated using D(z) above, and the overflow depth of aflow path in the other shapes can be calculated using D(z) according tothat shape as appropriate and performing integration thereon.

Furthermore, in the case of (1), the flow paths may have differentshapes and be provided in different numbers at the multiple partitionplates 21. In that case, the overflow depth H_(i) is calculated for eachof the partition plates 21. Here, i is an index (an integer of one ormore) for identifying the partition plates 21. It is sufficient that, ineach chamber, the weir height on the inlet side is higher than the weirheight on the outlet side by at least the overflow depth H_(i) at thepartition plate 21 on the outlet side.

(2) The Case in which the Reactor is Inclined and there is No HeightDifference Between the Partition Plates

Next, the case will be described in which the reactor 13 is inclined torealize the same effects as in the case where a height difference isprovided between the partition plates 21. It is assumed that the weirheights of the partition plates 21 are the same in the case where thereactor 13 is not inclined. Furthermore, the flow paths have the sameshape and are provided in the same number at all of the multiplepartition plates 21. That is to say, if the cross-sections inside thereactor 13 in a direction orthogonal to the length direction of thereactor 13 do not change, all the partition plates 21 may have the sameshape. Also in this case, if the reactor 13 is inclined such that theweir height on the inlet side is higher than the weir height on theoutlet side by at least the overflow depth at the partition plate 21 onthe outlet side in each chamber as shown in FIG. 8 when the content 20flows, that is, when the content 20 is treated, the same effects can berealized as in the case where a height difference is provided betweenthe partition plates 21 as described above. It will be appreciated thatthe reactor 13 is inclined such that the inlet side of the content ispositioned on the upper side and the outlet side is positioned on thelower side.

Hereinafter, an inclination angle in the case where the reactor 13 isinclined will be described. As shown in FIG. 9, the length of thechamber 33 in the length direction of the reactor 13 is taken as L.Although there is no limitation on length L, it is, for example,approximately 10 to 300 cm, preferably approximately 10 to 100 cm.Furthermore, it is assumed that the reactor 13 is inclined by an angle θsuch that the inlet side is higher than the outlet side. Furthermore,the overflow depth at the partition plate 21 on the outlet side in thechamber 33 is taken as H. Accordingly, the weir height of the partitionplate 21 on the inlet side of the chamber 33 and the weir height of thepartition plate 21 on the outlet side are different from each other byH0=L sin θ. Accordingly, in order to make the weir height on the inletside higher than the weir height on the outlet side by the overflowdepth at the partition plate 21 on the outlet side, it is sufficientthat H0=H, that is, L sin θ=H. Note that H can be calculated by solvingthe equation in description of the case in which a height difference isprovided between the partition plates 21. Accordingly, θ=sin⁻¹(H/L) isobtained using the calculated H together with L. If the reactor 13 isinclined by at least θ, the weir height on the inlet side is higher thanthe weir height on the outlet side by at least the overflow depth H atthe partition plate 21 on the outlet side. If all chambers have the samelength, the thus calculated θ may be used. Otherwise, it is necessary touse L that is the length of the shortest chamber. The reason for this isthat the θ corresponding to the length of the shortest chamber is thelargest value. Accordingly, “L” in θ=sin⁻¹(H/L) may be the shortestlength of the lengths, in the length direction of the reactor 13, of therespective chambers.

Note that, if the reactor 13 is inclined, in the strict sense, thepartition plates 21 are also inclined. Thus, the flow path at thepartition plates 21 is also inclined by the angle θ. Accordingly,strictly speaking, the overflow depth is different from the value of Hobtained by solving the above-described equation, but the angle θ istypically a small value, and the difference in H depending on thepresence or absence of the inclination is also small. Furthermore, sinceH is typically sufficiently small compared with L, there is no problemeven if a change in H according to the inclination of the reactor 13 isnot taken into consideration. It will be appreciated that the overflowdepth H may be calculated taking the inclination of the reactor 13 intoconsideration as well, and the thus calculated H may be used to obtainthe angle θ. FIG. 10 shows an exemplary internal structure in the casewhere the reactor 13 is inclined.

Furthermore, also in the case where the reactor 13 is inclined, the lastchamber 34 may be considered as in the case of (1). That is to say, theoverflow depth at the outlet is calculated, and θ is calculated asdescribed above, also for the last chamber 34. The reactor 13 may beinclined by at least the larger value of θ calculated for the lastchamber 34 and θ calculated for the other chambers.

(3) The Case in which the Reactor is Inclined and there is a HeightDifference Between the Partition Plates

The above-described (1) and (2) may be combined. That is to say, in eachchamber, the weir height on the inlet side can be made higher than theweir height on the outlet side by at least the overflow depth at thepartition plate 21 on the outlet side, by making the reactor 13 inclinedand providing a height difference between the partition plates 21. Inthat case, the weir height of the partition plate 21 on the inlet sidemay be higher than the weir height of the flow path at the partitionplate 21 on the outlet side by at least “H−L sin θ”. Note that H is theoverflow depth at the partition plate 21 on the outlet side, L is theshortest length of the lengths, in the length direction of the reactor13, of the respective chambers, and θ is the inclination angle of thereactor 13. Furthermore, also in this case, it is assumed that the flowpaths have the same shape and are provided in the same number at thepartition plates 21, and the inclination angle of the reactor 13 is notso large.

In the description of (1) to (3) above, the overflow depth H iscalculated using the shape of the flow path, the flow rate, and thelike, but there is no limitation to this. The overflow depth H may bemeasured in the state where the content is actually caused to flowinside the reactor 13. Further, the flow paths at the partition plates21 may be designed or the inclination angle of the reactor 13 may beadjusted such that, in each chamber, the weir height on the inlet sideis higher than the weir height on the outlet side by at least theoverflow depth on the outlet side. In that case, the flow paths may nothave the same shape and may not be provided in the same number at thepartition plates 21. That is to say, the flow paths may have differentshapes, may be provided in different numbers, or may have differentshapes and be provided in different numbers, at the partition plates 21.Furthermore, if the overflow depth is measured, the reactor 13 may bemade openable and closable above the unfilled space 22, or may beprovided with a window through which the inside of the reactor 13 can beobserved from above the unfilled space 22. In the latter case, thewindow preferably does not transmit microwaves, but, if the windowtransmits microwaves, the window may be covered by a material that doesnot transmit microwaves during irradiation of microwaves, and, only atthe time of observation, the irradiation of microwaves may be stoppedand the cover may be opened to perform the observation. In this case,the reactor 13 being openable and closable refers to the configurationin which the reactor 13 is provided with a lid member that can be openedand closed. The lid member may be, for example, an upper face plate ofthe reactor 13, may be a door-like member, or may be another openableand closable member. Furthermore, if the overflow depth is measured, forexample, scales for measuring the overflow depth may be provided at theflow paths at the positions of the partition plates 21.

In the case of the first chamber 31 of the reactor 13, that is, thechamber into which the content is loaded from the outside, the contentis typically loaded from above as shown in FIG. 2 and the like. Thus,consideration of the conditions relating to the partition plates 21 andthe inclination angle as in the case of (1) to (3) described above isnot necessary. However, if the content is caused to flow horizontallyinto the first chamber 31 as in the case of the following chambers, alsoin the first chamber 31, the weir height on the inlet side (the heightof the bottom of the flow path) may be set higher than the weir heighton the outlet side by at least the overflow depth at the partition plate21 on the outlet side, as described above.

Furthermore, the flow path at the partition plates 21 may or may notinclude a flow path that allows the content to flow through a void ofthe partition plates 21 in addition to the flow path that allows thecontent to flow over the partition plates 21. That is to say, “thecontent flows over each of the partition plates 21” refers to that atleast the overflow-type flow path is present, and does not refer to thatanother flow path should not be present. In the former case, that is, ifthere is a flow path that allows the content to flow through a void ofthe partition plates 21, the void may be a void 27 provided through thepartition plate 21 as shown in FIG. 4C, may be a void 27 between thepartition plate 21 and the reactor 13 as shown in FIG. 4D, or may beboth voids. There is no limitation on the shape, the position, and thenumber of voids 27. Furthermore, if the partition plate 21 has the void27, it is preferable that the content through the void 27 does not flowin a shortcut. Accordingly, for example, adjacent partition plates 21may be arranged such that the partition plate 21 shown in FIG. 4C andthe partition plate 21 shown in FIG. 4D are alternately arranged.Furthermore, if the partition plate 21 has the void 27, the overflowdepth H may be calculated taking the flow rate through that void intoconsideration as well, or the overflow depth H may be measured asdescribed above. Furthermore, if the partition plate 21 has the void 27,the flow path through the void 27 may allow part of the content to flowfrom the downstream side to the upstream side.

In the case where the reactor 13 is not inclined, the object can berealized also by making, in each chamber, the weir height on the inletside higher than the weir height on the outlet side by at least fivetimes or ten times the overflow depth at the partition plate 21 on theoutlet side. However, with this configuration, a difference between theliquid surfaces of the respective chambers increases, and the capacityof the chamber decreases toward the downstream side, so that the amountof material that can be treated by the reactor 13 decreases.Accordingly, it is preferable that the difference between the weirheight on the inlet side and the weir height on the outlet side in eachchamber is not extremely large, although the difference has to be atleast the overflow depth at the partition plate 21 on the outlet side.The difference between the weir heights may be, for example,approximately one to three times the overflow depth on the outlet side.Furthermore, also in the case where the reactor 13 is inclined, thecapacity of each chamber decreases as the inclination angle isincreased. Accordingly, it is preferable that the inclination angle isset such that the difference between the weir height on the inlet sideand the weir height on the outlet side in each chamber is not extremelylarge, although the difference has to be at least the overflow depth atthe partition plate 21 on the outlet side. Also in this case, theinclination angle may be set such that the difference between the weirheights is, for example, approximately one to three times the overflowdepth on the outlet side. Note that, since the content flows into orflows out of each chamber, the height of the liquid surface may slightlyincrease or decrease in each chamber. Accordingly, as a precautionarymeasure, the partition plates 21 may be designed or the reactor 13 maybe inclined such that, in each chamber, the difference between the weirheight on the inlet side and the weir height on the outlet side isapproximately two to three times the overflow depth on the outlet side.Furthermore, if agitation is performed using the agitation units 23, thepartition plates 21 may be designed or the reactor 13 may be inclined,using the overflow depth H when no agitation is performed.

Hereinafter, a specific example for computing the overflow depth and thelike will be described. If flow rate Q=1000 (liter/hour)≅2.78×10⁻⁴(m³/s), width a of bottom of flow path=0.01 (m), width b of upper sideof flow path=0.1 (m), height e of flow path=0.05 (m), flow coefficientC=0.6, number N of flow paths=3, and acceleration of gravity g=9.807(m/s²),H=0.017 (m).In the equation, H is obtained by numerical computation. Accordingly, inthe case of (1) above, it is sufficient that, in each chamber, the weirheight of the partition plate 21 on the upstream side is higher than theweir height of the partition plate 21 on the downstream side by at least1.7 cm. Accordingly, for example, the partition plates 21 may bedesigned such that the weir height of the partition plates 21 in thereactor 13 decreases stepwise by 2 cm toward the downstream side.Furthermore, in the case of (2) above, if the length L of eachchamber=0.5 (m), then θ=0.035 (rad)=2.0°. Accordingly, it is sufficientthat the reactor 13 is inclined by 2°.

Next, an operation of the chemical reaction apparatus 1 according tothis example will be briefly described. The raw material and thecatalyst are supplied by the pumps 11 to the mixing portion 12, aremixed in the mixing portion 12, and are loaded into the reactor 13. Thespeed of the raw material and the like supplied to the reactor 13 may bepreferably in accordance with the flow rate Q.

The raw material and the like supplied to the reactor 13 flow from theupstream side to the downstream side while being agitated by theagitation units 23. The microwaves generated by the microwave generators14 are transmitted via the waveguides 15 to the unfilled space 22 in thereactor 13, and are irradiated on the raw material and the like. At thattime, overflows are not directly connected as described above, and,thus, the content can be prevented from flowing in a shortcut, and thecontent can be efficiently irradiated with microwaves. The raw materialand the like are heated with the microwaves, and the reaction of the rawmaterial and the like is facilitated. Note that the temperatures of thechambers 31 to 34 are measured by the temperature measuring portions 25,and are passed to the microwave control portion 16 via a route that isnot shown. Then, the microwave control portion 16 controls the power ofthe microwave generators 14 such that the temperatures of the chambers31 to 34 are at a desired temperature or in a desired temperature range.

The product material discharged from the reactor 13 is loaded into thecatalyst separating portion 17 where the catalyst is separatedtherefrom. Then, the product material from which the catalyst has beenseparated is loaded by the pump 11 into the treated liquid storage tank18. In the treated liquid storage tank 18, the product material isseparated into a target product and a by-product. In this manner, afinal product is obtained. Furthermore, such treatment is repeatedlyperformed, and, thus, a target product is sequentially produced.

Note that the treatment that separates the catalyst in the catalystseparating portion 17 and the treatment that separates the productmaterial into a product and a by-product in the treated liquid storagetank 18 may be performed sequentially each time the product material isloaded, or may be performed at a time when the amount of productmaterial loaded accumulates and reaches a certain amount. That is tosay, the treatment in the reactor 13 is of a flow-type (flowthrough-type), but the treatment in the catalyst separating portion 17and the treated liquid storage tank 18 on the path thereafter may be ofa flow-type, or may be of a batch-type.

Furthermore, there is no limitation on the chemical reaction caused tooccur in the chemical reaction apparatus 1 according to this example, aslong as it is a chemical reaction that is caused to occur by microwaveirradiation itself or by heat due to microwave irradiation. For example,the chemical reaction may be production of biodiesel fuel throughesterification or transesterification, may be production of ink rawmaterial that is ester, or may be other chemical reactions.

Next, a case will be described in which biodiesel fuel (fatty acidmethyl ester) is produced from waste oil using the chemical reactionapparatus 1 according to this example. It will be appreciated that thepresent invention is not limited to this reaction.

Reaction System Construction Example

As the raw material, a mixture of fat and oils and free fatty acid, andalcohol are used. The alcohol is used as a reactant. The raw materialand the catalyst are sent by the pumps 11 into the mixing portion 12,and are uniformly mixed. The mixed liquid is supplied to the reactor 13.The mixed liquid inside the reactor 13 is irradiated with the microwavesgenerated by the microwave generators 14, and, thus, the esterificationreaction is facilitated. Furthermore, the mixed liquid inside thereactor 13 is loaded into the chambers 31 to 34 that have beenpartitioned from each other by the partition plates 21 inside thereactor 13. The mixed liquid together with the catalyst is irradiatedwith microwaves while being agitated by the agitation units 23, and,thus, the reaction progresses. The microwaves are irradiated on theunfilled space 22 inside the reactor 13, and are diffused inside thereactor 13. The reaction liquid in each chamber moves to its nextchamber through a flow path provided at the partition plates 21. Thereaction liquid is held inside the reactor 13 for a certain retentiontime, and then is discharged out of the reactor 13. The mixed liquidafter the reaction discharged out of the reactor 13 is supplied to thecatalyst separating portion 17. After the catalyst is separated in thecatalyst separating portion 17, the mixed liquid is loaded into thetreated liquid storage tank 18. From the reaction liquid after thecatalyst separation, water and glycerin that are by-products are furtherseparated in the treated liquid storage tank 18, and, thus, crude methylester that is a target product is obtained. The microwave power of thereactor 13 is subjected to feedback control based on the temperaturesinside the chambers 31 to 34, and, thus, the temperatures of thechambers 31 to 34 are kept constant. For example, the reactiontemperature may be set at 70° C.

As described above, with the chemical reaction apparatus 1 according tothis example, overflows can be prevented from being directly connectedin the horizontal direction between the chambers, by changing the heightof the flow path at the partition plates 21, making the reactor 13inclined, or applying both of these configurations. Accordingly, thecontent can be prevented from flowing in a shortcut, so that the contentcan be irradiated with microwaves as appropriate. As a result, anunreacted content is prevented from being discharged out of the reactor13, and the yield in the chemical reaction apparatus 1 can be improved.Since the content inside the reactor 13 is agitated using the agitationunits 23, the content can be uniformly irradiated with microwaves evenin the case where the depth to which microwaves penetrate is not sodeep. Furthermore, since the reactor 13 is partitioned into multiplechambers, the content undergoes a reaction while being retained in eachchamber, and, thus, the content can be effectively irradiated withmicrowaves in each chamber. Furthermore, if the solid catalyst ismicrowave-absorbing or microwave-sensitive, the solid catalyst isefficiently heated through microwave irradiation, and, thus, thechemical reaction near the solid catalyst can be facilitated. In thismanner, the chemical reaction inside the reactor 13 is facilitated, and,thus, a product material can be more efficiently obtained.

Note that, in this example, the case has been mainly described where thereactor 13 in which the area of the liquid surface does not changeaccording to a change in the amount of the content is shaped such thatthe side face of the reactor 13 extends in the normal direction of theliquid surface as shown in FIGS. 3A and 3B, but there is no limitationto this. The reactor 13 may have a shape in which the area of the liquidsurface does not change according to a change in the amount of thecontent also in the case where the side face of the reactor 13 extendsin a direction different from the normal direction of the liquidsurface. This configuration is realized, for example, in the case wherethe reactor 13 is installed so as to be inclined as shown in FIG. 10.

Furthermore, the case has been described with reference to FIG. 2 whereeach chamber has the agitation unit 23, but there is no limitation tothis. Multiple chambers may have a single or multiple agitation units23. If the chemical reaction apparatus 1 has a single agitation unit 23,as described above, the agitation unit 23 may have a shaft (rotationalshaft) shared by multiple chambers. In that case, the agitation unit 23may include a rotational shaft, multiple rotatable members, and arotating unit. The rotational shaft is a shaft extending in the flowdirection in the reactor 13. For example, in FIG. 2, the rotationalshaft may extend from the left end face to the right end face of thereactor 13. The rotational shaft may be provided in parallel to thebottom face of the reactor 13. For example, this rotational shaft may bemade of a microwave-transmitting material, a microwave-absorbingmaterial, a microwave-reflecting material, or a combination of two ormore freely selected from these materials. If the rotational shaft ismade of a microwave-reflecting material (e.g., metal, etc.), microwavesirradiated on the rotational shaft are reflected. Accordingly, if therotational shaft is present above the liquid surface of the contentinside the reactor 13 in this case, part of the microwaves is reflectedby the rotational shaft and is not irradiated on the content.Accordingly, in order to avoid such a situation, it is preferable thatthe liquid surface of the content is positioned above the rotationalshaft, that is, the rotational shaft is present inside the content.Furthermore, if the rotational shaft is made of a microwave-absorbingmaterial, microwaves irradiated on the rotational shaft are absorbed.Accordingly, if the rotational shaft is present above the liquid surfaceof the content inside the reactor 13 in this case, part of themicrowaves is absorbed by the rotational shaft and is not irradiated onthe content. Furthermore, the heat of the rotational shaft mayabnormally increase. Accordingly, in order to avoid such a situation, itis preferable that the liquid surface of the content is positioned abovethe rotational shaft, that is, the rotational shaft is present insidethe content. Accordingly, the amount of the content may be controlledsuch that the liquid surface of the content is above the rotationalshaft, or the reactor 13 may have a shape in which the cross-sectionalarea in the liquid surface direction does not change at least above therotational shaft. For example, as shown in FIG. 3C, the height of theliquid surface at the lowest level in the range R1 in which the area ofthe liquid surface does not change may be set to the height at which thecontent just covers a rotational shaft 28. Accordingly, if the liquidsurface is within the range R1, the area of the liquid surface does notchange, and the liquid surface is positioned above the rotational shaft28. Note that, in FIG. 3C, the radius of the semicylindrical shapeforming the lower portion of the reactor 13 is preferably in accordancewith the rotational radius of the rotatable members rotating about therotational shaft 28. This configuration can effectively prevent asituation in which part of the content at the bottom of the reactor 13fails to be agitated. Furthermore, for example, in the case of thereactor 13 shown in FIG. 3D in which the area of the liquid surface doesnot change as long as the height of the liquid surface of the content iswithin the range R1, which covers the entire height, the control can beperformed such that the area of the liquid surface does not change, andsuch that the liquid surface is positioned above the rotational shaft28, by keeping the height of the liquid surface within the range R2. Theheight of the liquid surface at the lowest level in the range R2 is setto the height at which the content just covers the rotational shaft 28.Note that “above” and “below” are directions along the verticaldirection. The same is applicable to “upper side” and “lower side”.Furthermore, “vertical direction” is a direction perpendicular to thehorizontal plane. The flow direction in the reactor 13 is the flowdirection of the content in the reactor 13, and is typically the same asthe length direction of the reactor 13. The rotatable members aremembers that rotate about the rotational shaft. When the rotatablemembers rotate, the content is rotationally agitated. The rotatablemembers may be, for example, blade-like members, wing-like members,rod-like members, or the like, as described above. Furthermore, eachchamber may have such a rotatable member, but there is no limitation tothis. There may be a chamber having no rotatable member. Furthermore,one chamber may have two or more rotatable members. It is sufficientthat the agitation units 23 have at least one or more rotatable members.The rotating unit rotates each rotatable member. If the rotatablemembers are fixed to the rotational shaft, the rotating unit may be aunit for rotating that rotational shaft. In that case, the rotating unitmay be, for example, a motor, an engine, or the like. Furthermore, therotational shaft may not rotate, but may support the rotatable member ina rotatable manner. In that case, for example, the rotating unit mayrotate a rotatable member having a magnet, using a magnetic force.Specifically, as in the case of a motor that rotates a rotor configuredby a permanent magnet, using a stator configured by an electromagnetprovided around the rotor, it is possible to rotate the rotatable member(rotor) using the rotating unit (stator). Note that, in that case, therotating unit that is a stator is preferably disposed outside thereactor 13, but there is no limitation to this. The reason for this isthat, depending on the material forming the reactor 13, the rotatingunit that is a stator cannot be disposed outside the reactor 13.Furthermore, if the agitation units 23 have a rotational shaft extendingin multiple chambers, holes through which the rotational shaft extendsmay be formed in the partition plates 21. Furthermore, if there is arotational shaft extending in multiple chambers, the rotational shaftmay extend through the voids 27 of the partition plates 21.

Furthermore, in this example, the case has been described where thereactor 13 has a shape in which the cross-section in the liquid surfacedirection of the content does not change as long as the amount of thecontent is within a predetermined range, but there is no limitation tothis. If the reactor 13 has a shape that ultimately prevents the area ofthe liquid surface from changing according to a change in the amount ofthe content as long as the amount of the content is within apredetermined range, it is not necessary that the cross-section in theliquid surface direction of the content does not change. Specifically,even in the case where the cross-section in the liquid surface directionof the content changes from one shape (e.g., rectangle, etc.) to anothershape (e.g., trapezoid, etc.) according to the height of the liquidsurface, as long as the cross-sectional area in the liquid surfacedirection of the content is the same throughout the height of the liquidsurface, it can be said that the reactor 13 has a shape in which thearea of the liquid surface does not change according to a change in theamount of the content even in the case where the cross-section in theliquid surface direction of the content changes.

Furthermore, in this example, the case has been described where thereactor 13 has a shape in which the area of the liquid surface does notchange even in the case where the height of the liquid surface changesaccording to a change in the amount of the content as long as the amountof the content is within a predetermined range, but there is nolimitation to this. The area of the liquid surface may change accordingto a change in the amount of the content.

Furthermore, in this example, there is no limitation on the number ofrotational shafts or rotating units in the agitation units 23. Forexample, a single rotational shaft and a single rotating unit may beused to rotate one or more rotatable members, or two or more rotationalshafts and two or more rotating units may be used to rotate two or morerotatable members.

In this example, the case has been described where the mixing portion 12that mixes the raw material and the catalyst is provided, but there isno limitation to this. For example, if a premixure of the raw materialand the catalyst is used, if the mixing is also performed by the reactor13, if the solid catalyst that flows inside the reactor 13 is retainedin the reactor 13, or if a solid catalyst forming a fixed bed is usedinstead of the solid catalyst that flows inside the reactor 13, thechemical reaction apparatus 1 does not have to be provided with themixing portion 12. Note that, if a solid catalyst forming a fixed bed isused, typically, the solid catalyst forming a fixed bed is providedinside the reactor 13. The solid catalyst forming a fixed bed may befixed, for example, by being pasted on the inner wall of the reactor 13,or by being placed in a catalyst filled layer, a column, or the likeinside the reactor 13. Examples of the shape of the solid catalystinclude various grains, a cylinder (that may or may not be hollow), asphere, a pellet, a ring, a shell, a honeycomb, a foam, a fiber, acloth, a plate, and other shapes.

Furthermore, in this example, the case has been described where thereactor 13 has four chambers 31 to 34 that are continuously arranged inseries as shown in FIG. 2, but there is no limitation on the number ofchambers. Typically, as the number of chambers increases, a situationcan be more effectively prevented in which the raw material flows in ashortcut from the inlet to the outlet of the reactor 13. Furthermore, ifthe capacity of each chamber does not change regardless of an increaseor a decrease in the number of chambers, the retention time from whenthe content of the reactor 13 flows into the reactor 13 to when thecontent flows out of the reactor 13 becomes longer as the number ofchambers increases, and the retention time becomes shorter as the numberof chambers decreases. Accordingly, in this case, the number of chamberscan be adjusted such that a desired retention time is obtained.

Furthermore, in this example, the case has been described where themultiple microwave generators 14 are provided, but there is nolimitation to this. For example, the microwaves generated by themicrowave generator 14 may be transmitted via a branched waveguide 15 tomultiple locations as shown in FIG. 11. The multiple locations may be,for example, multiple chambers. FIG. 11 shows the case in which thechemical reaction apparatus 1 is provided with only one microwavegenerator 14, but, in the case where the chemical reaction apparatus 1is provided with two or more microwave generators 14, the microwavesgenerated by any one of the multiple microwave generators 14 may betransmitted via the branched waveguide 15 to multiple locations. Forexample, if the microwaves generated by the microwave generator 14 aretransmitted to multiple chambers, the microwave control portion 16 maycontrol the power of that microwave generator 14 using any or all of thetemperatures of the chambers to which the microwaves generated by themicrowave generator 14 are transmitted. For example, the microwavecontrol portion 16 may perform the control using an average of alltemperatures of the chambers, or may perform the control using a maximumvalue or a minimum value of the temperatures of the chambers.

Furthermore, in this example, the case has been described where thechemical reaction apparatus 1 is provided with the temperature measuringportions 25 and the microwave control portion 16, but there is nolimitation to this. For example, if it is possible to keep thetemperature inside the reactor 13 at a desired temperature or in adesired temperature range by setting the power of microwaves to apredetermined value, the control of the power of microwaves using thetemperature does not have to be performed.

Furthermore, in this example, the case has been described where thecatalyst separating portion 17 is provided on the path after the reactor13, but there is no limitation to this. If the catalyst does not have tobe separated by the chemical reaction apparatus 1 according to thisexample, as in the case in which the catalyst is separated by anotherapparatus, the case in which the solid catalyst that flows inside thereactor 13 is retained in the reactor 13, the case in which a solidcatalyst forming a fixed bed is used instead of the solid catalyst thatflows inside the reactor 13, or the case in which no catalyst is used inthe chemical reaction in the reactor 13, the catalyst separating portion17 does not have to be provided.

Furthermore, in this example, the case has been described where the rawmaterial and the catalyst are mixed and loaded into the reactor 13, butthere is no limitation to this. For example, only the raw material maybe loaded into the reactor 13. Furthermore, if the raw material and thecatalyst are not mixed, only the raw material may flow inside thereactor 13. That is to say, the content of the reactor 13 may be, forexample, a mixture of multiple raw materials. Furthermore, even in thecase where the raw material and the catalyst are not mixed, for example,the raw material and the catalyst may flow inside the reactor 13 whenthe solid catalyst that flows inside the reactor 13 is retained in thereactor 13. Furthermore, if the raw material and the catalyst are notmixed, the mixing portion 12 may, for example, mix the raw material, ormix the raw material (substrate) and the reactant. Furthermore, if theraw material and the like do not have to be mixed, the chemical reactionapparatus 1 does not have to be provided with the mixing portion 12 asdescribed above.

Furthermore, in this example, the case has been described where one ormore agitation units 23 that agitate the raw material inside the reactor13 are provided, but there is no limitation to this. For example, if thereactor 13 is configured such that the entire raw material can be easilyirradiated with microwaves (e.g., if the inner diameter of the reactor13 is small, etc.), the agitation units 23 do not have to be provided.

Furthermore, in this example, the case has been described where thechemical reaction apparatus 1 is provided with the treated liquidstorage tank 18, but there is no limitation to this. For example, amixture of the product material and the by-product discharged from thechemical reaction apparatus 1 may be subjected to extraction of theproduct material and the like in another apparatus.

Furthermore, in this example, the chemical reaction apparatus 1 may beprovided with two or more microwave generators 14, and the two or moremicrowave generators 14 may generate microwaves having two or morefrequencies. That is to say, the content of the reactor 13 may beirradiated with microwaves having two or more frequencies. In that case,the microwaves having two or more frequencies may be irradiated on thesame position, or may be respectively irradiated on different positions.For example, as shown in FIG. 12A, microwaves having frequencies X and Yrespectively generated by microwave generators 14 a and 14 d may beirradiated on the same position in the reactor 13, that is, at themidstream in the reactor 13. Note that the microwaves having thefrequencies X and Y are respectively transmitted via waveguides 15 a and15 d to the reactor 13. Furthermore, for example, as shown in FIG. 12B,microwaves having a frequency X generated by microwave generators 14 a,14 b, and 14 c may be irradiated on the side from the upstream to themidstream in the reactor 13, and microwaves having a frequency Ygenerated by a microwave generator 14 d may be irradiated on thedownstream side in the reactor 13. Note that the microwaves having thefrequency X are respectively transmitted via waveguides 15 a, 15 b, and15 c to the reactor 13. Furthermore, the microwaves having the frequencyY are transmitted via a waveguide 15 d to the reactor 13. FIGS. 12A and12B are both views of the reactor 13 from above, wherein the arrows inthe drawings indicate the flow of the content inside the reactor 13. Ifmicrowaves having two or more frequencies are irradiated, the number offrequencies may be two, or three or more. There is no limitation on thecombination of two or more frequencies, as long as they are selectedfrom the range from 300 MHz to 300 GHz. For example, if microwaveshaving two frequencies are irradiated, examples of the combination ofthese frequencies include 2.45 GHz and 5.8 GHz, 2.45 GHz and 24 GHz,2.45 GHz and 913 MHz, 5.8 GHz and 24 GHz, 5.8 GHz and 913 MHz, and 24GHz and 913 MHz. Furthermore, if microwaves having two or morefrequencies are irradiated, there is no limitation on the irradiationtiming. For example, microwaves having two or more frequencies may besimultaneously irradiated, or may be irradiated respectively indifferent irradiation periods. For example, in the latter case,microwaves having the frequency X may be irradiated in one period, andmicrowaves having the frequency Y may be irradiated in the next period.Furthermore, if microwaves having two or more frequencies areirradiated, the microwaves having two or more frequencies may beintroduced to one unfilled space 22, or may be introduced to differentunfilled spaces 22. In the latter case, there are at least two or moreunfilled spaces 22 that have been separated from each other by thepartition plate 21 inside the reactor 13. Note that if microwaves havingtwo or more frequencies are irradiated, a material that is not affectedby the action (e.g., heating, etc.) of microwaves having one frequencycan be also affected, and, thus, a wider range of materials can beaffected by the microwaves.

Furthermore, in the foregoing example, information relating to theprocessing performed by each constituent element, for example,information that is to be accepted, acquired, selected, produced,transmitted, or received by each constituent element, information suchas a threshold value, a numerical expression, or an address used in eachconstituent element in the processing and the like may be retained in anunshown storage medium temporarily or for a long period of time even ifnot specified in the description above. Furthermore, information may beaccumulated in the unshown storage medium by each constituent element orby an unshown accumulating unit. Furthermore, information may be readfrom the unshown storage medium by each constituent element or by anunshown reading unit.

Furthermore, in the foregoing example, if information used in eachconstituent element or the like, for example, information such as athreshold value, an address, or various setting values used in eachconstituent element in the processing may be changed by a user, the usermay change such information as appropriate even if not specified in thedescription above, but there is no limitation to this. If the user maychange such information, the change may be realized by, for example, anunshown accepting unit that accepts a change instruction from the userand an unshown changing unit that changes information according to thechange instruction. The change instruction may be accepted by theunshown accepting unit, for example, by accepting information from aninput device, by receiving information transmitted via a communicationline, or by accepting information read from a predetermined storagemedium.

Furthermore, in the foregoing example, each constituent element may beconfigured by dedicated hardware, or, alternatively, constituentelements that can be realized by software may be realized by executing aprogram. For example, each constituent element may be realized by aprogram execution unit such as a CPU reading and executing a softwareprogram stored in a storage medium such as a hard disk or asemiconductor memory.

Furthermore, it will be appreciated that the present invention is notlimited to the example set forth herein, and various modifications arepossible within the scope of the present invention.

INDUSTRIAL APPLICABILITY

As described above, the chemical reaction apparatus according to thepresent invention is effective in that a content can be prevented fromflowing in a shortcut, and, thus, it is useful, for example, as achemical reaction apparatus for performing microwave irradiation.

The invention claimed is:
 1. A chemical reaction method, comprising the steps of: preparing a chemical reaction apparatus comprising the steps: partitioning an inside of a horizontal flow reactor into multiple chambers by multiple partition plates, and flowing a liquid content horizontally with an unfilled space being provided thereabove; generating microwaves with a microwave generator; and transmitting the microwaves generated by the microwave generator, with at least one waveguide, to the unfilled space in the reactor; forming a top portion of the partition plates act as a weir; configuring a weir height of each of the partition plates in the reactor; at least one of: calculating an angle θ as; θ=sin⁻¹(H/L) wherein L is a shortest length, in a length direction of the reactor, of each of the chambers, and H is an overflow depth obtained using the following equation: 15eQ=√{square root over (2g)}CN{4(b−a)H ^(5/2)+10aeH ^(3/2)} wherein Q is a flow rate of the liquid content, a is a width of a bottom of a trapezoidal flow path, b is a width of an upper side of the trapezoidal flow path, e is a height from the bottom to the upper side of the trapezoidal flow path, C is a flow coefficient, N is a number of trapezoidal flow paths formed at each of the partition plates where each of the partition plates includes one or more trapezoidal flow paths, and g is an acceleration of gravity; or obtaining the angle θ by reading from a storage medium in which the angle θ was calculated and stored in advance; inclining the reactor at an angle of inclination of at least the angle θ; and flowing the liquid content over each of the partition plates inside the reactor; wherein the weir height of each of the partition plates in the reactor is the same in a state where the reactor is not inclined, and wherein the weir height on the inlet side is higher than the weir height on the outlet side by the overflow depth at each of the partition plates on the outlet side where the reactor is inclined at the angle θ.
 2. The chemical reaction method according to claim 1, further comprising a step of controlling the microwave generator to maintain a uniform predetermined temperature or a predetermined temperature range over all chambers inside the reactor.
 3. The chemical reaction method according to claim 1, further comprising a step of determining the flow rate. 